What is it ?

Tempest for Eliza is a Program that uses your computer monitor
to send out AM radio signals. You can then hear computer
generated music in your radio.

this document first describes tempest for eliza, the old program that
plays music like your cellphone does when you get a phonecall. then it
describes tempest for mp3 which you can use to play mp3 files :-)

How does this work ?

All electronic devices send out eletromagnetic waves.
so does your monitor. and your monitor does it all the time.
and at very high frequencies. high enough for your short wave
AM radio.
all you have to do is display the "correct" image on your screen
and your monitor will emit the "right" signals.
Tempest for Eliza displays pictures on your screen. one for
each note in the song.

[Note: Markus G. Kuhn's and Ross J. Anderson's paper; "Soft Tempest:
Hidden Data Transmission Using Electromagnetic Emanations" was used as a
reference when programming Tempest-AM. This paper is a must read before
going further testing Tempest-AM. The paper is availabe from
I strongly recommend to read the paper thoroughly.]

Why this program ?

You need no additional hardware to understand that it is
really possible to observe your computer without
physically touching it. (tempest).
I wrote this program because it was fun and because
it teaches in an amusing way that tempest really exists.
i want people to understand that their computers can
be observed.
And last but not least you can listen to music without a soundcard!
I know it's an old topic ,but again...

Tempest for Eliza